Low emission tin catalysts

ABSTRACT

Plastic articles with low emission obtainable by polymerization, condensation, and/or cross-linking reaction including the use of metal catalysts wherein said metal catalyst has a low emissivity and is an organotin compound of the general formula R 2 SnX 2  wherein R is a C 1 -C 8 -hydrocarbyl, X is a carboxylate group with 14-20 carbon atoms having at least one olefinic double bond. Moreover, the invention relates to the use of an organotin compound in the manufacture of plastic articles with low emissivity of said organotin compound.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to the use of simple tin catalysts forthe manufacturing of polyurethane foams with significantly reducedemission. More particularly, the present invention is related to the useof dialkyltin dicarboxylates R₂SnX₂ which are derived from carboxylicacids with particularly low emissivity, but provide high activity forcatalyzing the reaction of isocyanates with polyols and are highlycompatible with the components of typical polyurethane formulations.

2. Description of Related Art

Tin compounds are well known as very effective catalysts for themanufacturing of polyurethanes, silicones, and polyesters.

Polyurethanes are basically manufactured by reaction of isocyanates withis polyols. Commonly used isocyanates are either aromatic or aliphaticdi- or polyisocyanates, commonly used polyols are eitherpolyetherpolyols or polyesterpolyols. Polyurethanes derived fromaliphatic isocyanates have the general advantage of a better lightstability than polyurethanes derived from aromatic isocyanates.Aliphatic isocyanates are generally less reactive than aromaticisocyanates and hence require particularly strong catalysts; typicallyorganotin catalysts are used, either alone or in combination with othercatalysts.

Polymers, and in particular polyurethanes are of increasing importancein the manufacturing of modern car interiors. E.g. U.S. Pat. No.5,656,677 teaches the use of polyurethane foams derived from aliphaticisocyanates for the manufacturing of light stable car interiors.

A general problem connected with the use of plastics in car interiors isthe emission of volatile organic compounds at elevated temperatures;said volatile organic compounds may form condensate films on the carwindows, reducing the visual transparency and thereby causing the socalled “fogging effect”. The emissivity (“fogging”) properties of aplastic material are determined either by the amount (by weight) ofcondensate formed under defined conditions, or by the loss oftransparency caused by this condensate on a glass sheet.

Modern plastic materials are formulations of different base materialsand additives, which can separately or in combination contribute to thefogging. Several efforts have been undertaken to reduce the fogging fromplastic materials by optimising base materials and additives. Inmanufacturing of polyurethanes, e.g., major achievements have alreadybeen made by the introduction of purified polyesterpolyols (with reducedcontents of volatile cyclic esters), and by the elimination of volatileantioxidant additives (see e.g.: EP 1153951 to Bayer; DE 19611670 toBASF; G. Baatz, S. Franyutti, Paper 9, UTECH '94 Conference,. 1994, TheHague).

Facing increasingly tight regulations and consumer demands, furtherreductions of emission levels are required. After elimination of theprevious main contributors, further improvement has to target the so-farneglected minor additives. Among said additives, particularly urethanecatalysts contribute to the fogging.

Common catalysts for the urethane reaction are tertiary amines, stannoustin compounds, dialkyltin compounds, and compounds of other metals. Thementioned classes of catalysts may contribute to fogging either becauseof their own volatility (e.g. amines), or by formation of volatilereaction products or degradation products. Attempts have been reportedto reduce the fogging properties of said catalysts: using catalystswhich are reactive with isocyanates can lead to firm fixation of thosecatalysts in the polymer matrix and thereby reduce fogging. Examples forisocyanate-reactive amines are given e.g. in EP0799821 (and in theliterature cited there). Examples for isocyanate-reactive dialkyltincatalysts are given e.g. in EP0417605. A general drawback of suchisocyanate-reactive catalysts is their reduced catalytic activity. Also,reaction with the isocyanate and incorporation into the polymer matrixchanges the polymer properties.

A useful polyurethane catalyst must have high activity for the urethanereaction, and a sufficiently high selectivity for the urethane reactionover undesired side reactions. Furthermore, it should be storage stable,readily soluble in and compatible with the polyols and/or theisocyanates, and best be liquid at ambient temperature.

Dialkyltin compounds are well known for their strong catalytic power inpolyurethane reactions, and are often indispensable in order to achievethe required material properties. Particularly useful are dialkyltindicarboxylates. Among the dialkyltin dicarboxylate polyurethanecatalysts, dimethyltin dicarboxylates are the strongest.

The most common carboxylate types for dialkyltin dicarboxylate catalystsare acetate, 2-ethylhexanoate, neodecanoate, and laurate. All dialkyltincarboxylates containing these carboxylate types contribute to fogging,not only by their own volatility, but particularly by the volatility oftheir degradation products, the most important being the correspondingcarboxylic acids.

It can be reasonably expected that dialkyltin dicarboxylates derivedfrom car-carboxylic acids with longer alkyl chain than lauric acid wouldcontribute less to fogging.

When simply the length of the carboxylate alkyl chain of a dialkyltincarboxylate is further increased (e.g. to saturated C₁₃-C₁₇), onesignificant drawback is a decrease in the catalytic activity. Even moreimportant drawbacks are the higher melting points (e.g. dimethyltindimyristate approx. 70° C., dimethyltin dipalmitate approx. 80° C.), thelimited solubility in the typical main components of polyurethaneformulations (i.e. polyols and/or isocyanates), and the limitedcompatibility with said main components.

Certain dialkyltin dicarboxylates having 13 or more carbon atoms and atleast one olefinic double bond in the carboxylate alkyl chain are liquidat ambient temperature. Example are oleates, ricinoleates, linolates,and linoleates of dimethyltin and dibutyltin.

E.g., dimethyltin dioleate has been described as a heat stabiliser forPVC. No reference to polyurethane catalysis was made. Furthermore, GB1250498 teaches the use of a “basic dimethyltin oleate” as a curingcatalyst for silicone rubbers. Said “basic dimethyltin oleate” isdescribed as a “Harada complex” R₂₅ nA₂*R₂SnO; according to the modernstate-of-the-art, it would be called1,1′,3,3′-tetramethyl-1,3-oleoyloxo-1,3,2-stannoxane.

E.g., dibutyltin dioleate has been described as a heat stabiliser forPVC, as solvent extraction agent for arsenate ions, as catalyst foresterifications, as catalyst for curing of silicones and as catalyst forcuring of electrodeposition coatings. One publication (R. V. Russo, J.Cell. Plast. 12, (1976), 203) reported comparative testing of dibutyltindioleate as polyurethane foam catalyst, but said article teaches thatdibutyltin dioleate is a particularly poor catalyst. No reference toemissivity was made.

E.g., use of dioctyltin diricinoleate has been reported as apolyurethane gelation catalyst, having reduced toxicity (U.S. Pat. No.4,332,927 to Caschem). No reference to emissivity was made.

SUMMARY OF TH INVENTION

The present invention is directed to low emission organotin compounds ofthe general formulaR₂SnX₂wherein R is C₁-C₈-hydrocarbyl, preferred are methyl and butyl,particularly preferred is methyl. X is a carboxylate group with 14-20carbon atoms having at least one olefinic double bond, optionallysubstituted; preferred are oleate, ricinoleate, linoleate andlinolenate; particularly preferred is oleate.

These compounds can be used as low emission catalysts in all fields ofapplications where organotin compounds are known to be useful ascatalysts. Such fields include, but are not limited to, catalysis ofesterification and transesterification reactions, condensation curing ofRTV II silicones, curing of cataphoretic electrodeposition coatings,deblocking of blocked isocyanates, and, especially, curing of thesynthesis of polyurethanes by the reaction of isocyanates with polyols.Advantageous is particularly the low emissivity, but high activity forcatalyzing the reaction of isocyanates with polyol, and highcompatibility with the typical components of polyurethane formulations.

The invention is further directed to the use of said organotin compoundsas catalysts for the production of low emission polyurethanes,particularly for use in car interiors. Especially preferred is the useof said catalysts for the production of polyurethanes derived fromaliphatic isocyanates. The inventive catalysts can be used alone or incombination with other catalysts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to low emission dialkyltindicarboxylates of the general formulaR₂SnX₂R is a C₁-C₈-hydrocarbyl group. Typically, R is an aliphatic, saturated,unbranched, and not further substituted alkyl group, such as methyl,ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl,.Preferred alkyl groups are methyl, butyl, and octyl. Particularlypreferred is methyl. X is a carboxylate group derived from a carboxylicacid of the typeR′—COOHwherein R′ is a C₁₃-C₁₉-hydrocarbyl group having one or more olefinicdouble bonds. Typically, R′ is an aliphatic and unbranched alkenylgroup; it may be further substituted, e.g., with one or more hydroxygroups. The alkenyl group may be present in the cis-form, or in thetrans-form, or a mixtures of both forms. Preferred carboxylate groupsare oleate, ricinoleate, linoleate and linolenate. Particularlypreferred is oleate.Said low emission dialkyltin dicarboxylates can be synthesised fromcommercially available raw materials using standard synthesis methodsfor dialkyltin dicarboxylates; e.g. by reaction of dialkyltin oxideswith carboxylic acids, or by reaction of dialkyltin dichlorides withalkali carboxylates, or by reaction of dialkyltin dichlorides withcarboxylic acids and bases, etc.Said low emission dialkyltin dicarboxylates are liquid at roomtemperature, or melt at a low temperature slightly above roomtemperature. They are well soluble or mixable with polyetherpolyolsand/or polyesterpolyols, which are widely used in the manufacturing ofpolyurethanes. Several of said low emission dialkyltin dicarboxylatesare soluble in aliphatic and/or aromatic isocyanates, which are widelyused in the manufacturing of polyurethanes. When dissolved, they have anexcellent compatibility with said polyols and isocyanates, and do notprecipitate from solution when stored at ambient temperature. Whendissolved in isocyanates, they do not promote the formation ofisocyanurates (isocyanate trimers), which is a common side-reaction ofseveral other organotin catalysts.Said low emission dialkyltin dicarboxylates have only very lowvolatility, and when degraded by hydrolysis, alcoholysis, acidolysis, orrelated reactions, the degradation products formed therefrom also haveonly very low volatility.Said low emission dialkyltin dicarboxylates have a high but at leastsufficient catalytic activity for catalyzing the reaction of isocyanateswith alcohols to form urethanes.

The present invention is further directed to the use of said lowemission dialkyltin dicarboxylates as catalysts for the production oflow emission polyurethanes or polysilicones.

Said low emission polyurethanes or polysilicones produced by to the useof said low emission dialkyltin dicarboxylates may appear in any formgenerally applicable to polyurethanes or polysilicones, as foams (rigid,flexible, high resiliency, integral, microcellular), RIM, RRIM,elastomers, coatings, etc.

By use of said low emission dialkyltin dicarboxylate catalysts, anygeneral type of low emission polyurethane or polysilicone may beproduced: foams (rigid, flexible, high resiliency, integral,microcellular . . . ), RIM, RRIM, elastomers, coatings, etc.

Preferred low emission polyurethanes are polyurethane foams.

Also preferred low emission polyurethanes are light stable polyurethanesderived from aliphatic isocyanates.

In manufacturing of low emission polyurethanes, the inventive lowemission dialkyltin dicarboxylate catalysts can be used either alone orin combination with other catalysts. Especially, the well know synergyof dialkyltin compounds with tertiary amines in the catalysis of theurethane reaction may be used to enhance the catalytic power of theinventive dialkyltin dicarboxylate catalysts. Also, in the production ofwater blown foam, tertiary amine catalysts may be used to speed anddirect the reaction of isocyanates with water. Examples of furthercommon catalysts which may be used together with the inventive catalystsinclude metals compounds of stannous tin, Ti, Pb, Hg, Bi, Fe, Ni . . .

In production of a polyurethane, the inventive low emission dialkyltindicarboxylate catalysts can be either added prior to the reaction to thepolyol component, or to the isocyanate component, or it can be admixedwith other additives to form a master blend, or it can be added directlyto the reaction mixture.

The isocyanates commonly used in the production of polyurethanes arewell know to those skilled in the art. Examples include TDI (toluenediisocyanate, typically mixtures of the para-isomer, and theortho-isomer), MDI (4,4′-diphenylmethane diisocyanate), polymeric MDI,IPDI (isophorone diisocyanate), HDI (hexamethylene diisocyanate). Theisocyanates are either used as such, or can also be used in a blockedform; when used in a blocked form, the blocking agent has to be cleavedof the isocyanate shortly before or during the processing.

The polyols commonly used in the production of polyurethanes are alsowell known to those skilled in the art. The most important classes arepolyesterpolyols and polyetherpolyols, which are basically polyesterresp. polyether chains, terminated and optionally further substitutedwith isocyanate-reactive hydroxyl groups. E.g., the most commonly usedpolyetherpolyols are derived from ethylen oxide and/or propylene oxide.

The polyurethane may contain further additives (like blowing agents,foam stabilisers, chain extenders, flame retardants, fillers, pigmentsetc.), known to those skilled in the art.

The present invention is further directed to the use of said lowemission polyurethanes for use in car interiors.

The advantages and the important features of the present invention willbe more apparent from the following examples.

EXAMPLES

Glossary:

Polyol 1 is a 3500 MW polyether polyol, (OH-No. approx. 38) availablefrom Elastogran as Lupranol 3032.

Polyol 2 is a 4700 MW polyether polyol (OH-No. approx. 36), availablefrom Shell Chemicals as Caradol ET 36-17.

Polyol 3 is a 6000 MW polyether polyol (OH-No. approx. 28), availablefrom DOW Chemicals as Voranol CP 6001.

Polyol 4 is a 6000 MW polyether polyol (OH-No. approx. 32-35), availablefrom DOW Chemicals as Voranol CP 1421.

Isocyanate 1 is toluene diisocyanate (TDI, mixture of 80% para, and 20%ortho).

Isocyanate 2 is Isophorone diisocyanate (IPDI).

Isocyanate 3 is 4,4′-Diphenylmethane diisocyanate (MDI 2447).

Foam stabiliser 1 is a silicone, available from Crompton Corp. as NiaxRS-171.

Amine cocatalyst 1 is Diethanolamine (DEOA).

Amine cocatalyst 2 is blend of bis(dimethylaminoethyl)ether anddipropylene glycol, available from Crompton Corp. as Niax A-1.

EXAMPLE 1 Preparation of the Catalysts

1 a) Preparation of Dimethyltin Dioleate from Dimethyltin Dichloride

Into a 3-neck glass flask, equipped with a mechanical stirrer,thermometer, dropping funnel, and pH glass electrode, were placed 44 gof dimethyltindichloride (0.2 mol) and 44 g of water. The mixture wasstirred until the dimethyltindichloride is completely dissolved. 113 gof oleic acid (0.4 mol) were added and the mixture was heated to 60° C.

An aqueous NaOH solution (35.5% by weight) was placed into the droppingfunnel. While stirring, the NaOH solution was slowly added to thereaction mixture. NaOH addition was stopped when a pH of approx. 6 hadbeen reached.

The mixture was heated to approx. 80° C., then the stirrer was stoppedand the phases allowed to settle.

The phases were separated and the lower (aqueous) phase discarded. Theorganic phase was dried in a rotary evaporator at approx. 80° C./1 mbar,and subsequently further dried with Na2SO4. Finally, 1% of Celite (afilter aid) were added and the product was filtered.

Yield: 136.6 g of dimethyltin dioleate (96.0% of theor.). The productwas a clear yellow liquid, and contained 15.8% Sn (theor. 16.7%), and0.0% Cl (theor. 0.0%).

1 b) Preparation of Dimethyltin Dioleate from Dimethyltin Oxide

Into a 3-neck glass flask, equipped with a mechanical stirrer,thermometer, and a vacuum connector, were placed 57.7 g of dimethyltinoxide (0.35 mol) and 197.6 g of oleic acid (0.7 mol). While stirring,the mixture was heated to 40° C., and a vacuum of 10 mbar was applied.During 1 hour the temperature was slowly risen to 70° C., and wassubsequently held for another hour. Subsequently a vacuum of 1 mbar wasapplied, and the reaction mixture was further stirred for 1 more hour.

The vacuum was broken, and the reaction mixture was allowed to cool toroom temperature. Finally, 1% of Celite (a filter aid) were added andthe product was filtered.

Yield: 245.8 g of dimethyltin dioleate (98.7% of theor.). The productcontained 16.5% Sn (theor. 16.7%).

It was a clear yellow liquid, having a viscosity of 100 mPa·s. It wasmiscible with Polyols 1, 2, and 3. It was readily soluble in Isocyanates1, 2, and 3.

A 1% solution (by weight) of the product in Isocyanate 2 was preparedand stored at 25° C. After 3 weeks the solution was still clear, nosolid material had formed and the infrared spectrum of the solution didnot show the carbonyl band of an isocyanurate.

1 c-g) Preparation of Further Dialkyltin Dicarboxylates

Following the procedure described in example 1 b, the followingmaterials were synthesised (see table 1): TABLE 1 Yield Exper- (% ofiment Dialkyltin oxide Carboxylic acid Product theor.) 1c Dibutyltinoxide Oleic acid Dibutyltin oleate 97.6 1d Dioctyltin oxide Oleic acidDioctyltin oleate 97.2 1e Dimethyltin oxide Ricinoleic acid Dimethyltin96.3 ricinoleate 1f Dimethyltin oxide Linoleic acid Dimethyltin 96.9linoleate 1g Dimethyltin oxide Linolenic acid Dimethyltin 98.1linolenate

EXAMPLE 2 Catalyst Activity Tests Viscosity Measurement in ElastomersCased on Aromatic Isocyanates (IDI)

80 g of Polyol 1 were placed at room temperature into a dry 100 mLwide-neck glass bottle. 0.0002 mol of the respective organotin catalystwere added. The mixture was stirred for 2 minutes to dissolve thecatalyst.

0.036 mol of Isocyanate 1 were added, and the mixture stirred for 2 moreminutes. The bottle was then placed under a Brookfield rotaryviscosimeter. The raw mixture had a Brookfield viscosity of <<1 Pa·s.Sample temperature and viscosity were recorded until the mixture becametoo viscous for further measurement (>25 Pa·s). In each experiment, thetime of isocyanate addition to the polyol considered as the start of thereaction (t=0 min). Results are summarised in table 2. TABLE 2 Example2a 2b 2c 2d Catalyst Dibutyltin Dimethyltin Dimethyltin dilauratedineodecanoate dioleate (comparison) (comparison) No Catalyst TimeViscosity Viscosity Viscosity Viscosity (min) (mPa * s) (mPa * s) (mPa *s) (mPa * s) 0 2 4 800 600 1100 600 6 1000 800 1300 600 8 1300 1000 1900600 10 1800 1400 2900 600 12 2400 1800 4700 600 14 3200 2200 7800 600 164100 2900 14000 600 18 5300 3600 >25000 600 20 7200 4400 600 22 92005500 600 24 12100 6800 600 26 16100 8400 600 28 21700 10300 60030 >25000 13100 600

EXAMPLE 3 Catalyst Activity Tests Viscosity Measurement in ElastomersBased on Aromatic Isocyanates (TDI)

Example 2 was repeated with the difference that after mixing of allcomponents at room temperature the glass bottle was immersed in an oilheating bath. The oil bath was heated at a nearly constant rate fromroom temperature to 100° C., and was than held at this temperature(heating to 100° C. takes typically approx. 20 minutes). In eachexperiment, the time of isocyanate addition to the polyol considered asthe start of the reaction (t=0 min). Results are summarised in table 3.TABLE 3 Example 3a 3b 3c 3d Catalyst Dibutyltin Dimethyltin Dimethyltindilaurate dineodecanoate dioleate (comparison) (comparison) No CatalystTime Viscosity Temp. Viscosity Temp. Viscosity Temp. Viscosity Temp.(min) (mPa * s) (° C.) (mPa * s) (° C.) (mPa * s) (° C.) (mPa * s) (°C.) 0 2 4 800 38 900 37 1200 34 600 34 6 900 48 1000 46 1300 40 500 42 8900 58 1000 54 1500 48 500 51 10 1000 65 1000 63 1900 59 400 59 12 130072 1400 73 3200 71 200 67 14 2400 80 3100 83 6800 83 <200 77 16 5000 906600 87 >25000 91 <200 84 18 >25000 95 >25000 91 <200 92 20 <200 95

EXAMPLE 4 Viscosimetric Catalyst Activity Tests Elastomer Based onAliphatic Isocyanate(IPDI)

75 g of Polyol 2 were placed at room temperature into a dry 100 mLwide-neck glass bottle.

In a dry glass flask, 0.00016 mol of the respective organotin catalystand 5,6 g of Isocyanate 2 are mixed by stirring.

The isocyanate/catalyst mixture is added to the polyol at roomtemperature, and the mixture stirred for 2 more minutes. The glassbottle was immersed in an oil heating bath, placed under a Brookfieldrotary viscosimeter. The oil bath was heated at a nearly constant ratefrom room temperature to 100° C., and was than held at this temperature(heating to 100° C. takes typically approx. 20 minutes). The raw mixturehad a Brookfield viscosity of <<1 Pa·s. Sample temperature and viscositywere recorded until the mixture became too viscous for furthermeasurement (>25 Pa·s). In each experiment, the time of isocyanateaddition to the polyol considered as the start of the reaction (t=0min). Results are summarised in table 4. TABLE 4 Example 4a 4b 4c 4d 3eCatalyst Dibutyltin Dimethyltin Dimethyltin Dibutyltin dilauratedineodecanoate dioleate dioleate (comparison) (comparison) No CatalystTime Viscosity Temp. Viscosity Temp. Viscosity Temp. Viscosity Temp.Viscosity Temp. (min) (mPa * s) (° C.) (mPa * s (° C.) (mPa * s) (° C.)(mPa * s) (° C.) (mPa * s) (° C.) 0 1 2 3 600 34 900 35 700 33 500 38400 36 4 500 39 800 40 500 38 700 43 <200 39 5 400 41 600 43 700 43 60048 <200 42 6 400 47 200 49 700 50 500 54 <200 47 7 700 55 700 57 700 58800 61 <200 53 8 900 64 1100 66 600 67 1100 69 <200 60 9 1300 72 1100 721200 74 1800 76 <200 66 10 2100 78 1800 78 1800 80 3400 81 <200 71 114300 83 4200 83 2600 84 8400 85 <200 76 12 9700 87 7900 87 520087 >25000 88 <200 80 13 >25000 89 >25000 90 11900 90 <200 83 14 >2500092 <200 86 15 <200 88

EXAMPLE 5 Preparation of Polyurethane Foams Water Blown Foams fromPolyether Polyols and Aromatic Isocyanate (MDI)

100 g of Polyol 3 and 2 g of Polyol 4 were mixed and placed into acardboard cup.

A master blend was made of 3.6 g of water, 0.5 g of Foam stabiliser 1,0,6 g of Amine cocatalyst 1, and 0.15 g of Amine cocatalyst 2. The blendwas added to the polyol and mixed.

0.5 g of the resp. organotin catalyst was added to the mixture and themixture was stirred for 2 minutes.

61.8 g of Isocyanate 3 (index 100) were quickly added to the mixture.The mixture was stirred for 10 seconds, and than poured into a cardboardbox.

A polyurethane foam formed and expanded. Cream time and rise time of thefoam were recorded.

Results are summarised in Table 5. TABLE 5 Example 5a 5b 5c CatalystDibutyltin Dimethyltin Dimethyltin dilaurate dineodecanoate dioleate(comparison) (comparison) Cream Time (s) 10 10 8 Rise Time (s) 54 44 45

EXAMPLE 6 Determination of the Fogging of Catalysts by Gravimetry

A dry, clean round piece of aluminum foil (diameter 103 mm, thickness0.03 mm) was weighed. 5 g of the resp. liquid organotin catalyst and 0.5g of water were placed onto the bottom of a dry and clean glass beaker(inner diameter 80 mm, outer diameter 90 mm).

A silicone rubber ring was fitted to the neck of the beaker, thealuminum foil was placed on top of it, and covered with a glass sheet(11 0×110×3 mm). The beaker was hang into a thermostated glycerolheating bath in such a way, that the glass sheet was 60 mm above theglycerol level. An aluminum cooling block (connected to anotherthermostat) was placed onto the glass sheet. For 16 hours, a glycerolbath temperature of 100° C., and a cooling block temperature of 21° C.was maintained. Subsequently, the aluminum foil was placed into adessicator and kept there for 1 hour at room temperature over silica.

The aluminum foil was then weighed again, and the weight difference (inmg) was recorded as mg of fogging condensate.

Results are summarised in Table 6. TABLE 6 Example 6a 6b 6c CatalystDibutyltin Dimethyltin Dimethyltin dilaurate dineodecanoate dioleate(comparison) (comparison) Fogging condensate 21.5 194.2 234.4 (mg)

EXAMPLE 7 Determination of the Fogging of Polyurethane Foams byGravimetry Foams Based on Polyether Polyols and Aromatic Isocyanate(MDI)

The foam samples prepared in Example 5 were cut into round disks (each80 mm in diameter, and 10 g of weight). Example 6 was repeated with thedifference, that instead of 5 g of the resp. liquid organotin catalystand 0.5 g of water, now the resp. foam disks were placed onto the bottomof the glass beaker.

Results are summarised in Table 7. TABLE 7 Example 7a 7b 7c Foam sampleFoam Foam prepared Foam prepared prepared with with Dibutyltin withDimethyltin Dimethyltin dilaurate dineodecanoate dioleate (comparison)(comparison) Fogging 1.15 1.51 3.45 condensate (mg)

In view of the many changes and modifications that can be made withoutdeparting from principles underlying the invention, reference should bemade to the appended claims for an understanding of the scope of theprotection to be afforded the invention.

1. A polyurethane article with low fogging characteristics derived froma polyurethane forming reaction mixture containing as a catalyst for themixture an organotin compound having low emissivity of the generalformulaR₂SnX₂ wherein R is methyl and X is a carboxylate group with 14-20carbon atoms having at least one olefinic double bond.
 2. Thepolyurethane article according to claim 1, wherein in said organotincompound X is a carboxylate group derived from a carboxylic acid of theformula:R′—COOH wherein R′ is a C₁₃-C₁₉ hydrocarbyl group having one or moreolefinic double bonds.
 3. The polyurethane article according to claim 2,wherein said one or more olefinic double bonds are isolated doublebonds.
 4. The polyurethane article according to claim 2, wherein R′ is asubstituted or unsubstituted alkenyl group.
 5. The polyurethane articleaccording to claim 2, wherein in said organotin compound saidhydrocarbyl and/or carboxylate group is a linear group.
 6. Thepolyurethane article according claim 2, wherein in said organotincompound the carboxylate group is selected from the group consisting ofoleate, ricinoleate, linoleate and linolenate.
 7. The polyurethanearticle according to claim 1, wherein said organotin compound is liquidat room temperature (20-25° C.).
 8. The polyurethane article accordingto claim 1, wherein said polyurethane article is a foamed article. 9.The polyurethane article according to claim 1, wherein in thepolyurethane forming reaction mixture comprises an isocyanate and apolyol. 10-11. (canceled)
 12. The polyurethane article according toclaim 9, wherein the polyol is selected from the group consisting ofpolyether polyols, polyester polyols and mixtures thereof.
 13. Thepolyurethane article according to claim 8, wherein the polyurethaneforming reaction mixture comprises an aliphatic isocyanate and a polyol.14. A process for preparing a polyurethane article having low foggingcharacteristics comprising the step of reacting simultaneously orsequentially an isocyanate with a polyol in the presence of an organotincompound having low emissivity of the general formulaR₂SnX₂ wherein R is methyl and X is a carboxylate group with 14-20carbon atoms having at least one olefinic double bond.
 15. The processaccording to claim 14, wherein in said organotin compound X is acarboxylate group derived from a carboxylic acid of the formula:R′—COOH wherein R′ is a C₁₃-C₁₉ hydrocarbyl group having one or moreolefinic double bonds.
 16. The process according to claim 14, wherein insaid organotin compound the carboxylate group is selected from the groupconsisting of oleate, ricinoleate, linoleate and linolenate.
 17. Theprocess according to claim 14, wherein said organotin compound is liquidat room temperature (20-25° C.).
 18. The process according to claim 14,wherein said polyurethane article is a foamed article.
 19. The processaccording to claim 14, wherein the step of reacting is a condensationreaction.
 20. An interior lining contained within a motor vehicle, theinterior lining comprising the polyurethane article of claim
 1. 21. Aninterior lining contained within a motor vehicle, the interior liningcomprising the polyurethane article of claim
 6. 22. An interior liningcontained within a motor vehicle, the interior lining comprising thepolyurethane foam of claim 8.